Hot-blast stove.



H A. BRASSERT & H. H. JONES. HUT BLAST STOVE. APPLICATION FILED NOV- |3| 9'5.

7 1,238,097; Patented Aug. 28,1917.

3 SHEETS-SHEET I H. A. BRASSERT & H. H. IONES.

HOI BLAST STOVE. I

APPLICATION FILED NOII. I3. IBIS, 1,238,097. Patented Aug. 28, 1917.

3 SHEETSSHEET 2- sum: was we .L|mn.. WAsmucnmIl c.

H..A. BRASSERT & H. H. JONES.

HOT BLAST STOVE.

APPLICATION rnrn NOV. I3. l9l5.

1 38,097, 7 Patented Aug. 28, 1917.

3 SHEETS-SHEET 3 HERMANN A. imjassnar Ann.

iARD I-I. JONES, or cnrcaeo, ILLINOIS.

notr nnas'r STGVE.

Specification of Letters Patent.

Patented Au as, raw.

Application filed November 13, 1915. Serial No. 61,2'2'1.

To all whom it may concern:

Be it known that we, HERMANN A. Baassnrrr and HOWARD H. Jones, both citizens of the United States,-residing in Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in HotBlast Stoves, of which the following is a specification.

- Our invention relates to improvements in hot blast stoves, and particularly to a method of and apparatus for heating the blast for use inblast furnaces.

- Hot blast stovesconsist of a cylindrical steel shell filled with checker brick. The

usual mode of operation ,isto heat these stoves by burning blast furnace gas in them for a period of time until thebrick work I is'heated to the desired degree and suflicient heathas been stored in the checkers. Then the gas is shut oil and .air from the blowing engines is admitted at the opposite end of the stove, flowingthrough in the opposite direction to the previous flow of the gas. Thus the heat stored in the stove is trans mitted from the brick work to the air, heating same to the desired temperature. inasmuch "as a large proportion of the total amount of blast furnace gas p'roduced by the furnace is used in thus heating'the blast, and inasmuch as the blast furnaceg-as has a commercial value equal to its equivalent n coal, it is very important that heatingof the blast in the hot blast stoves be done as eco nomically as possible.

In late years the Washing of blast furnace gas is coming into more general use. With clean gas it is possible to employ much smaller checker openings in the stoves without danger of their clogging up, and the heating surfaceof a stove of given size is very much increased. It is evident that the larger the heating surface the more complete will be the transmission of heat from the gases to the brick work and back again from the brick work to the blast. By the use of washed gas the heating surface of stovesmay be doubled and trebled by decreasing'the size ofchecker openings and greatly increasing their number. However, in order to derive the benefit of this improved construction it is necessary that the flow of the gas, as well as of the air, be equalized and that both be evenly dis.- tributed among the large number of checker openings and the entire area passes of the stove.

Our invention relates to the method as well as the construction of the apparatus, providing means for compelling an even distribution. It is a well known principle that a' current or flow of liquid can be equalized and more evenly spread 'over' a given area by putting a dam or weir across its passage, raising the head of water and compelling it to flow evenly over the entire face of the weir. Or baflles 0r screens placed in gas conduits have the same effect of spreading and equalizing the flow of gases. We have adopted this principle in hot blast stoves in the following manner.

they were 4% inches at the bottom they were inches at the top. WVe put one or more rows of smaller openings at the bottom of of the checker a pass, forming a restricted cross sectional area for the passage of the gases. After the air has entered the bottom of the stove and has filled the space-under the arches supporting the checkers, it is confrontedby this restriction and a slight back pressure is thereby created, compelling the air to divide equally among the many small openings before entering the largerones above. In the sainegmanner the How of the descending' gases is restricted and equalized. The provision of the smaller openings at the .bottom of the checkers results in a further advantage. In order to construct a checkerwork having the small openings most advantageously, it'is desirable to use small bricks. These small bricks, however, cannot well lie/adapted as a support between the checkers and the arches. fore, able to use larger bricks to properly support the checkers. necessarily restrict the size of the opening into the'checkers.

I am, there- These larger bricks the combusti n chamber, leaving the stove. through the hot hlaistfoutlet at n he ers 17.- In the presen ill-a wing 'h H jsjgnr'c 1 1s a vertical section through a hot blast stove constructed in accordance with our invention; 7

1 is similar vertical section of the l 'p' nd f the stove, the view being taken at right angles to th of shis. his sectional view o the hue of Fig: 1, ithtl 4 5 are sectional views on the linea t a d :5resphttivtly 9f il- In the drawing the steel shell is. ind a ed by the numeral 19, the d m as A gas burner 12 is provided in the lower end or the store; the Opening 1 @Qhhhfition it) tho chimney va ve. The cold blast inlet is indicated at 14, and the hot blast outlet at 15. A vertical combustion chamber 16 is provi d, which terminates in the dome, the heating cham Within the shell being filled with stan h We P at thelower of the checkers, two rows 15 of brick of larger si e which are r ec ly. suppor ed by the arches 19.- Thesslerger bricks provide for restricted flue openings?- The gas is burned n the c m n samba-1a the highly h e products of combustion reaching the me and g reversed in their directio of tra Passing downward through the checher 'h y reach the restricted openings Q m the two bottom rows of checkers. {h are f the fines at this point is reduced approximately one. third compared with the a a of the fiues in the Standard Checkers. The gases then enter the space below t arc es,

whence they escape through the chimney valve at 1.3. When the stove is reversed the cold blast @IltGiS through the opening. 14: near the point where the gases are drawn off and, to a certain X backs up 111 the space below the arche T for the reason tint the flow through the smaller openin 20 is restricted, thereby cau ing the an to be evenly distributed and to pass through all" of the checkers. As theair ascends through the checkers itgradually takes up the heat stored therein and flows downward through case Of the gases, these having passed through the combustion chamber and reversed their direction at the top under the dome, the natural. tendency is to flow toward the center checkers or those forming the nearest path to the point where the chimney valve is located. Our construction, however prevents this as the restriction in the bottom rows of the small checker openings is a far greater factor in the distribution of the gases than the effect of the location of indicates the the chimney valve, or the efi'ect of the gases tending to follow the hottest part of the stove hear the eaten t Wi l he hat We have counteracted all such influences in a very simple and efi'ective manner, and have thereby greatly increased the efiiciency of the stove.

While we have shown the invention as ap-' plied to a two pass stove, it will be understood that it may be applied with equal facility to three or four pass stoves, the same advantages accruing from the use thereof.

Our construction also has the advantage o'lf'g'reatly strengthening the support of the h k r wor With modern stores whi h,

are in many cases feet and more in.

height, great weight has to be supported at the bottom. With a decrease in the openings of'the checkers the walls of the checkers have been made thinner and at the pres-, ent tlme 2% and 2" walls are used, or of even less thickness It is impossible to get the necessary strength in these thin walls at the bottom over the arches. By restricting the checkerarea :in. the bottom rows, the

thickness of the brick may be increased there suliiciently to carry thegreat weight of the ckers F r n a We use 3" brick t support 2 1 and 2 checker walls.

Many deviations in the detailed construction and application of this restricted checker area may be devised without deviating from the'spirit or scope ofcur invention.

We claim: v.' t -i. 1. The method of heating the blast inhot blast stoves, which consists-inz'introducing the blast into the lower portion" of a heatin chamber, retarding the upward passage 0 said blast at the lower ends of the heated flues within said chamber, whereby said blast will be evenly distributed to said flues,

and expanding said blast and causing it to pass upwardly through said flues at substantially :uniform pressure and velocity, after the said retardation.

2. In a hot blast stove, 'a combination of checker-work composed of bricks laidin courses,v arches supporting said checker;

work, a course immediately above the sup porting arches-being composed of bricks of larger size; than the bricks employed in thebody of the checker-work, whereby the trans verse area of the fines is reduced only at the entrance to the flues and the gases are caused to be evenly distributed throughout the body of the checkers.

3. In a hot blast stove, a combination of I checker-work composed substantially entirely of'coursesof bricks of relatively thin section ands'mall size, arches supporting the checker-work, and a relatively very small number of coursesojf bricks of larger size,

each of which course is made up of a num= ber of bricks substantially equal to thc numarches, and distributing the gases through- 16 her employed in forming the courses in the out the checker-Work.

main body of the checkers, said courses com- Signed at South Chicago, Illinois, this 8th posed of large bricks being interposed be- .day of November, 19-15. tween said; main body of checker-Work HERMANN A. BBASSERT,

andjsaid arches, thereby reducing the area, HOWARD H. JONES. of the flues at that point, said large size Witnesses: bricks having the double function of trans- C. W. ROBERTSON,

mitting the Weight of the checkers to the B H. LAKE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. U." 

